Recently, demand for thermoplastic resin products having an antibacterial function has increased corresponding to increasing income levels and attention to personal health and hygiene. Hence, thermoplastic resin products subjected to antibacterial treatment so as to suppress or remove bacteria from surfaces of daily supplies and electronic products have increased in number, and it is a very important issue to develop an antibacterial material (antibacterial thermoplastic resin composition) having stability and reliability.
Antibacterial agents can be added to a thermoplastic resin composition to impart antibacterial properties thereto. Antibacterial agents can be classified as organic antibacterial agents and inorganic antibacterial agents.
Although organic antibacterial agents can be relatively inexpensive and can provide good antibacterial effects even with a small amount, organic antibacterial agents can often exhibit toxicity to the human body, provide inherent antibacterial effects against specific bacteria, and decompose and lose inherent antibacterial effects upon processing at high temperature. Moreover, organic antibacterial agents can cause discoloration after processing and can provide short antibacterial durability due to a problem of elution. Thus, organic antibacterial agents can be very restrictively applied to antibacterial thermoplastic resin compositions.
Inorganic antibacterial agents include an antibacterial agent containing a metallic component, such as silver (Ag) or copper (Cu). Although inorganic antibacterial agents are broadly used in the preparation of antibacterial thermoplastic resin compositions (antibacterial resins) due to good thermal stability thereof, inorganic antibacterial agents are generally required to be added in large amounts due to lower antibacterial effects than organic antibacterial agents. Moreover, inorganic antibacterial agents can have many problems, such as relatively high price, difficulty in uniform dispersion during processing, and discoloration due to the metallic component, and can have many limitations in use.
Therefore, there is a need for a thermoplastic resin composition which can secure good properties in terms of weather resistance (discoloration resistance), antibacterial properties (bacteria resistance) and antibacterial durability and can realize antifungal properties.